Gas-fueled lighter

ABSTRACT

A gas-fueled lighter comprises a fuel tank for liquified gaseous fuel, a burner structure having an inlet and an outlet, igniting means for igniting fuel issuing in gaseous state from the outlet, vaporizing means upstream of the inlet for receiving fuel in liquid state from the latter and supplying it in vaporized state to the inlet of the burner structure, and a throttling device interposed between the vaporizing means and the fuel tank so as to throttle the flow of fuel from the latter to the former. The throttling device is thermally insulated at least from the burner structure and the vaporizing means so as to prevent vaporization of fuel in the throttling device prior to entry into the vaporizing means.

United States Patent Inventor Peter Rabe Muhlheim/Main, Germany Appl. No. 840,352 Filed July 9, 1969 Patented June 29, 1971 Assignee Heinrich Maltner G.m.b.H.

Offenbach am Main, Germany Priority July 17, 1968 Germany GAS-FUELED LIGHTER 9 Claims, 3 Drawing Figs.

U.S.Cl 431/131 Int. Cl F23q 2/16 FieldoiSearch 431/129- References Cited UNITED STATES PATENTS 5/1964 Baumann 431/131 X n 13,ss9,ss1

3,390,945 7/1968 Wieden 43l/l3lX 3,465,355 9/1969 VanPoppel Primary Examiner Edward J. Michael Attorney-- Michael S, Striker ABSTRACT: A gas-fueled lighter comprises a fuel tank for liquified gaseous fuel, a burner structure having an inlet and an outlet, igniting means for igniting fuel issuing in gaseous state from the outlet, vaporizing means upstream of the inlet for receiving fuel in liquid state from the latter and supplying it in vaporized state to the inlet of the burner structure, and a throttling device interposed between the vaporizing means and the fuel tank so as to throttle the flow of fuel from the latter to the former. The throttling device is thermally insulated at least from the burner structure a d the vaporizing means so as to prevent vaporization of fu l in the throttling device prior to entry into the vaporizing means.

PATENTED JUN29 [8?! sum 1 OF 2 F igd lnren/ormuml S. Srnker AHorn 'Y GAS-FUELED LIGHTER BACKGROUND OF THE INVENTION The present invention relates to lighters in general, and more specifically to gas lighters.

Generally speaking, gas lighters may be divided into two broad categories according to the manner in which the gaseous fuel is supplied to the burner structure. One category supplies the burner structure directly from the gaseous phase of the liquefied gas contained in the fuel tank. The other type, known as liquid-gas lighters, supplies the burner structure with fuel directly from the liquid phase of the liquefied gaseous fuel contained in the fuel tank. This latter type, with which the present invention is concerned, has the advantage that no filler materials such as felt or the like need be accommodated in the interior of the tank. It is well known that the use of such filler materials, which are necessary in the type of gas lighter supplying the burner structure from the gaseous phase, presents certain problems which it has long been attempted to overcome.

The problem with the so-called liquid-gas lighters" is that it has heretofore been very difficult to obtain a quiet-buming stable flame of constant size. I-Ieretofore this type of gas lighter has been known for the fact that its flame pulses, flickers and is generally unsteady, particularly at low temperatures, for instance below C.

SUMMARY OF THE INVENTION It is, accordingly, a general object of the present invention to overcome these disadvantages.

More particularly, it is an object of the present invention to provide a gas lighter of the type under discussion which is not possessed of these disadvantages.

A still more specific object of the invention is to provide such a gas lighter which will operate reliably and with a steady flame in all operating conditions, even at low ambient temperatures. I

In pursuance of the above objects, and others which will become apparent hereafter, one feature of my invention recites in a gas-fueled lighter which comprises fuel tank means adapted to contain a supply of liquefied gaseous fuel, and burner means having an inlet and an outlet. Igniting means ignites fuel which issues in gaseous state from the outlet and vaporizing means is arranged upstream of the inlet and communicates with the same and with the fuel-tank means for receiving from the latter fuel in liquefied state and for supply ing this fuel in vaporized state to the inlet of the burner means.

Further, I provide a throttling device which is interposed between and communicates with the fuel-tank means and the vaporizing means for throttling the flow of fuel from the former to the latter. The provision of such throttling devices is already known. In accordance with the present invention, however, I thermally insulate the throttling device from the remaining components of the lighter in order to thereby prevent transmission of heat energy to the throttling device, because this can lead to premature vaporization of the fuel as it passes through the throttling device and prior to entry of the fuel into the vaporizing means, this being the reason for the unsteadiness of the flame in known lighter constructions of the type under discussion.

I have found that in all such lighter constructions of the prior art there exists a thermal bridge between the throttling device and the exterior of the lighter, particularly the surface portion of the lighter which is heated by the flame which develops when the lighter is in use. The existence of this thermobridge, that is the heat-exchanging relationship between the thus-heated exterior of the lighter and the throttling device, allows sufficient heat to be transmitted to the latter to cause partial vaporization of fuel passing through the throttling device. This, on the other hand, naturally results in the development of gas bubbles which impede the flow of fuel through the throttling device to the vaporizing means; in fact,

as a result of the volume increase of these gas bubbles the flow of fuel may be intermittently and temporarily interrupted. The result of all this is that fuel is erratically supplied through the vaporizing means to the burner means, and the flame is there fore unsteady because it does not receive a constant supply of fuel.

My invention overcomes this problem by preventing the transmission of heat to the throttling device, and by therefore preventing any vaporization of liquefied gas passing through the throttling device. vaporization takes place only upon passage of the liquefied gas through the vaporizing means, and the supply of gas through the throttling device is therefore not impeded. The result is a steady flame.

The present invention can be used with particular advantage in gas lighters of the type in question which have a fuel tank consisting of synthetic plastic material. Lighters having a metallic fuel tank with its relatively good thermo conduction are less affected by the problem in question because the comparatively large surface areas of the metallic fuel tank radiate a significant amount of the heat which is transmitted inwardly from the area of the flame and the surface heated by the flame, to the ambient atmosphere. Thus there is less heat available for heating the throttling device and causing the problems in question. This, however, requires that the fuel tank consist of material having good thermal conductivity so that the heat is rapidly conducted to the outer surfaces of the fuel tank for radiation thereby.'Synthetic plastic materials are poor thermal conductors and lighters utilizing fuel tanks consisting-of such materials therefore do not radiate the heat to the ambient atmosphere, with the result that the problems in question are much more pronounced in such lighters than they are in lighters having fuel tanks consisting of metallic material.

The throttling device includes a throttling element which in known manner may itself consist of thermally insulating porous material. This throttling element is thermally insulated in the manner still to be described in more detail hereafter. It is advantageous to assure that the throttling or flow resistance of the throttling device changes in dependence upon the ambient temperature, that is that the compensation is automatically efiected. The reason for this is that, as is well known, the pressure of the fuel in the fuel tank increases as the ambient temperature increases. This results in a higher flame because the fuel is forced out of the burner at greater pressure. Compensating devices for this purpose are already known, and may for instance consist of a metallic member and a throttling member of synthetic plastic material, the intention being to vary the flow resistance of the throttling device in dependence upon the ambient temperature to thereby maintain the height of the flame constant. However, the compensating devices provided for this purpose are influenced not only by the ambient temperature but also by the temperature of the burner structure and/or the throttling device itself, it has been found that the compensation provided is frequently entirely inadequate. In accordance with the invention this problem is avoided because the starting temperature of the throttling device, that is the temperature of the throttling device at the time the lighter is activated, and which temperature corresponds to the temperature of the liquefied gas in the fuel tank and thereby to the ambient temperature, is maintained constant or largely constant.

It will be clear that in accordance with the present invention it is essential that every effort be made to prevent the transmission of heat energy to the throttling device. By contrast, however, it is quite desirable that the vaporizing means, located downstream of the throttling device as seen with respect to the fuel flow, be in heat-exchanging relationship with heated portions of the lighter. The term heated" is of course relative in that no part of the lighter, including the burner structure, will necessarily get uncomfortably warm in the sense which is conventionally employed when the term heated is used. It should therefore be understood that the term heated as employed herein refers to any temperature rise of lighter components beyond the temperature which the lighter components would have if they did not receive heat energy-directly or indirectlyfrom develops when the lighter is activated.

The reason for desirably having the vaporizing means be in heat-exchanging relationship with heated components of the lighter is that this will aid in vaporization of the fuel as it passes through the vaporizing means. Whereas such vaporization is undesirable in the throttling device, it is clearly desirable that the vaporization be intentionally aided in the vaporizing means where it is legitimately intended to take place. The burner arrangements used in such lighters are usually very small, and the heat of vaporization of liquid gas is approximately lcal./g. C.; this heat of vaporization can be reliably provided under these circumstances only if the vaporizing means is deliberately made to-receive heat from heated components of the lighter; unless this is done, vaporization will not properly take place if the temperature of the liquid gas in the fuel tank falls below approximately C., as will be the case if the ambient temperature is low. Advantageously the vaporizing means will be composed of a porous material having good heat-exchanging properties of at least 10 and preferably in excess of 50kcal./m.h. C. (mean hour C.). In a material of this type vaporization takes place simultaneously in a plurality of parallel or substantially parallel fluid paths, and because of the large heat exchange surfaces bounding these various paths the supply of heat energy to the fuel is good and aids in the vaporization. The result is that at the downstream or outlet end of the vaporizing means there will at all times be available a substantially constant supply of fuel in gaseous state, regardless of the particular circumstances which may prevail in any given one of the plurality of individual paths at any given moment.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side-elevational view of a gas lighter embodying the present invention;

the flame which FIG. 2 is a fragmentary vertical section through a gas lighter of the type shown in FIG. 1, incorporating a first embodiment of the invention; and

FIG. 3 is a view similar to FIG. 1 but ofa gas lighter incorporating a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS swivel about a horizontal axis and simultaneously turns a nonillustrated spark wheel which cooperates in known manner with a flint. This is diagrammatically illustrated as the ignition means shown in chain lines and identified with reference character IM. I have refrained from showing this ignition means, or any of the others which can be similarly used, in any form other than the diagrammatic illustration in FIG. 1 because ignition means suitable for the purpose are well known to those skilled in the art and do not, in any case, form a part of my invention.

The lighter shown in FIG. 1 further comprises a burner unit 6 which is threaded into the tank 1, as diagrammatically shown, and a filling valve 7 is provided in the bottom of the tank I so that the latter may be filled with liquid gaseous fuel.

In FIG. 2 I show in a fragmentary enlarged section one embodiment of the invention, with the burner unit being illustrated in its closed position in which no gas can issue from the outlet. The arrow 8 in FIG. 2 indicates the closing force exerted by the cap 5 when the latter is in the position shown in FIG. 1. For the sake of clarity the cap 5 has been omitted in FIG. 2 and its operation, as well as that of the pressure valve 4 which activates the cap 5 as well as the ignition means, are well known to those skilled in the art and entirely conventional.

The fuel tank 1 is provided with threads 9 into which there is threaded a metallic housing 12, a sealing element 10 being interposed to prevent the escape of fuel. The housing 12 is in turn provided with threads 13 into which there is threaded a throttle-setting member 14 whose upper open end is provided with exterior teeth 15 and onto which a setting wheel 16 is pushed which is maintained in place by the teeth 15 so that rotation of the wheel 16 results in rotation of the member 14. An elastic annulus 17 of known construction prevents the wheel 16 from unintentionally coming off the member 14.

A tubular burner 18 is located in the interior of the member 14 and is shiftable in a telescopic member 20 against the force exerted by a spring 19. A valve member 21 is located below the member 20 and urged by contact with the same against a valve seat 22 when the burner 18 and the member 20 are shifted in the direction indicated by the arrow 8 in response to movement of the cap 5 from open position to the position illustrated in FIG. 1. An expansion spring 23 is provided which tends to lift the valve member 21 off its valve seat 22 when the force acting in the direction of the arrow 8 is relaxed or released. The operation of the valve and the operation and function of the burner are conventional and well known to those skilled in the art. They need therefore be further discussed, particularly inasmuch as they do not form a part of my invention.

An insert 24 is provided which is formed with the valve seat 22 and which is provided at its underside facing towards the interior of the fuel tank 1 with a recess in which there is lodged a disc-shaped porous vaporizing member 26 of a material having good thermally conductive properties. The edge face of the member 26 is in heat-exchanging contact with the insert 24. The outlet side of the member 26, that is the side at which vaporized fuel issues from the member 26 for entry into the valve 21, 22, is identified with reference numeral 27 and its surface is largely unobstructed. It is opposed by a slightly conical wall 28 of the insert 24 which tapers towards the outlet passage 29 closed by the valve 21, 22 when the structure is in the closure position shown in FIG. 2.

In accordance with the present invention the lower end of the metallic housing 12 is provided with a recessed generally cup-shaped extension 11 of synthetic plastic material which is secured to the housing 12 via screw threads 37. These screw threads 37 should advantageously be sealed and this may be accomplished by filling them with a sealing material, for instance a sealing material which hardens in the absence of air, such as the material known and commercially available under the trade name Loctite.

The extension 11 has a bottom wall 38 provided with an inlet aperture 34. Received in the recess of the extension 11 is a throttling element 30 which in the illustrated embodiment is composed of three discrete portions 31, 32 and 33 which may have different porosity. The material of the element 30 may be a porous elastically cross-linked polyurethane, such as the material which is commercially available under the trade name Zellvulkollan." interposed between the throttling element 30 and the insert 24 is an elastic sealing ring 36.

It will be noted that the throttling element 30 is substantially surrounded by thermally insulating material, namely on the one hand by the bottom wall 38 of the extension 1 l and on the other hand by the elastic sealing ring 36. There is, to be sure, a certain amount of transmission of heat energy to the element 30 from the vaporizing member 26 and from the metallic insert 24, and this can be simply counteracted by interposing a porous insulating layer 39, for instance consisting of filter paper. In actual practice, however, this is not normally necessary because the beginning of vaporization at the outlet side of the element 30, that is at the side proximal to the vaporizing member 26, is not normally objectionable in that it does not produce the problems which the invention is intended to overcome, or at least not to the extend that they would be noticeable. Such transmission of heat energy is confined, particularly if the element 30 itself consists of a material having poor thermal conductivity, to the region immediately adjacent the vaporizing member 26.

It will be appreciated that turning of the member 14 via the wheel 16 in a sense moving the member 14 downwardly as seen in FIG. 2, causes axial compression of the sealing member 36 with simultaneous compression in radial inward direction-outward escape of the material vof the sealing member 36 being prevented by the walls of the extension 11- whereby the throttling element 30 is axially and/or radially compressed so that in this manner the throttling resistance, that is the flow resistance of the element 30, can be regulated that is the flow resistance of the element 30, can be regulated with concomitant regulation of the height of the flame.

A plug 35 of porous material is located upstream of the aperture 34 and liquefied gas passes through this plug 35 from the interior of the tank 1 to the throttling element 30. This plug, also, is thermally insulated from the housing by the presence of the extension 11, so that the possibility that gas bubbles could develop in the plug 35 as a result of transmission of heat energy to the latter is avoided, or at least substantially reduced.

It can be assumed that the material of the element 30 and of the sealing ring 36 will undergo the largest volume changes of the various components, under the influence of changes in the ambient temperature. The termal expansion of the metallic components 12, 14 and 24 as well as of the synthetic plastic component 11 is negligible by comparison. This being the case, the construction shown in FIG. 2 provides for automatic temperature compensation of the throttling action of the element 30. In other words, compensation is made independence upon the temperature of the fuel contained in the tank 1, and accordingly in dependence upon the pressure prevailing in the tank I. The flow resistance provided by the element 30 at the time the lighter is first activated changes only insignificantly during the period of time for which the lighter is in use, that is during the period of time during which a flame burns at the outlet end of the burner tube 18. The reason for this is the heat insulation afforded by the material of the sealing ring 36 which' is cooled by the fuel with which it comes in contact and which. thus experiences an at most negligible temperature increase.

under the influence of heat supplied to it by the metallic components 12, 14 and 24. If, on the other hand, the fuel contained in the tank 1 has a substantially higher temperature, then the volume of the element 30 and the sealing ring 36 which are contacted by the liquefied fuel has increased and the flow resistance has increased concurrently. This increased flow resistance remains unchanged after. activation of the lighter and development ofa flame.

As is evident from FIG. 2, transmission of heat energy to the vaporizing member 26 is encouraged, rather that being suppressed. Such heat energy is imparted to the metallic components 14, 18 by the flame burning at the outlet end of the burner tube 18, and transmitted to the vaporizing member 26 by the insert 24. As mentioned before, the member 26 consists of material having good thermal conductivity. The fuel passing through the body 26 is therefore heated, which again means that its temperature is elevated in accordance with the comments made earlier, and vaporization is thereby aided with the result that'the fuel issuing in gaseous state from the outlet of the burner tube 18 provides for a very steady and quiet flame even at low ambient temperatures.

Corning, finally, to the embodiment illustrated in FIG.3 it will be seen that this is largely similar to that of FIG. 2. Like components are identified with like reference numerals.

By contrast to FIG. 2, however, the fuel tank 41 of the embodiment of FIG. 3 consists of synthetic plastic material. The housing 12 of FIG. 2 is replaced with a housing 42 also consisting of synthetic plastic material and being, in fact, of one piece with the fuel tank 41. The housing 42 is provided with threads 43. In the embodiment of FIG. 3 the sealing member 10 of FIG. 2 may be omitted. The sealing ring 36 prevents the fuel from bypassing the valve 21, 22 and escaping along the threads 43.

The synthetic plastic material of the fuel tank 41 and of the housing 42 is a poor thermal conductor, as is the material of the sealing ring 36 and, as pointed out earlier, that of the throttling element 30. Accordingly, heating of the metallic components 14, l8-and of course l6-will have no influence upon the throttling element 30 because no heat will be transmitted to the same. Conversely, however, heat can be readily transmitted via the metallic component 14 to the vaporizing body 26, and the construction of FIG. 3 has the same desirable advantages outlined above with respect to that of FIG. 2.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a gas-fueled lighter, it is not intended to be limited to the details shown, since variousmodifications and structural changes may be made without departing in any way from the spirit of the present invention. I

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended.

Iclaim:

- l. A gas-fueled lighter, comprising fuel-tank means adapted to contain a supply of liquefied gaseous fuel; burner means having an inlet and an outlet; ignitingmeans for igniting fuel issuing in gaseous state from said outlet; vaporizing means upstream of said inlet and communicating with the same and with said fuel-tank means for receiving fuel in liquid state from the latter and supplying it in vaporized state to the former; a throttling device interposed between and communicating with said fuel-tank means and said vaporizing means for throttling the flow of fuel from the former to the latter; and thermally insulating means thermally insulating said throttling device for preventing direct transmission of heat to fuel in said throttling device past said vaporizing means in response to transmission of heat to the region of said vaporizing means.

2. A lighter as defined in claim I, wherein said throttling device comprises a throttling element having an exposed surface, and said insulating means comprises a thermally insulating element thermally insulating said throttling element and in surface-to-surface contact with at least a portion of said exposed surface.

3. A lighter as defined in claim 1, wherein said throttling device consists at least in part of porous material having thermally insulating properties.

4. A lighter as defined in claim I, wherein said insulating means comprises a first portion of thermally insulating material provided with a recess having a bottom wall formed with a fuel passage communicating with said recess and said fuel tank means, and said throttling device comprising a second portion received in said recess disposed on said bottom wall and constituting a throttling element.

5. A lighter as defined in claim 4, wherein said fuel tank means consists of synthetic plastic material, and wherein said first portion is of one piece with said fuel tank means.

6. A lighter as defined in claim 4, wherein said second portion consists of yieldable porous material; said throttling device further comprising compressing means for subjecting said second portion to a variable compression whereby to adjust the throttling action of said throttling device.

7. A lighter as defined in claim 6, said compressing means including an engaging portion, and said insulating means comprising an annular. member of thermally insulating material interposed between said second portion and said engaging por- 8 exchanging contact with said burner unit for exchanging heat with said surface portion.

9. A lighter as defined in claim 8, wherein said vaporizing means comprises a vaporizing element composed of a porous material having good thermal conductivity. 

1. A gas-fueled lighter, comprising fuel-tank means adapted to contain a supply of liquefied gaseous fuel; burner means having an inlet and an outlet; igniting means for igniting fuel issuing in gaseous state from said outlet; vaporizing means upstream of said inlet and communicating with the same and with said fueltank means for receiving fuel in liquid state from the latter and supplying it in vaporized state to the former; a throttling device interposed between and communicating with said fuel-tank means and said vaporizing means for throttling the flow of fuel from the former to the latter; and thermally insulating means thermally insulating said throttling device for preventing direct transmission of heat to fuel in said throttling device past said vaporizing means in response to transmission of heat to the region of said vaporizing means.
 2. A lighter as defined in claim 1, wherein said throttling device comprises a throttling element having an exposed surface, and said insulating means comprises a thermally insulating element thermally insulating said throttling element and in surface-to-surface contact with at least a portion of said exposed surface.
 3. A lighter as defined in claim 1, wherein said throttling device consists at least in part of porous material having thermally insulating properties.
 4. A lighter as defined in claim 1, wherein said insulating means comprises a first portion of thermally insulating material provided with a recess having a bottom wall formed with a fuel passage communicating with said recess and said fuel tank means, and said throttling device comprising a second portion received in said recess disposed on said bottom wall and constituting a throttling element.
 5. A lighter as defined in claim 4, wherein said fuel tank means consists of synthetic plastic material, and wherein said first portion is of one piece with said fuel tank means.
 6. A lighter as defined in claim 4, wherein said second portion consists of yieldable porous material; said throttling device further comprising compressing means for subjecting said second portion to a variable compression whereby to adjust the throttling action of said throttling device.
 7. A lighter as defined in claim 6, said compressing means including an engaging portion, and said insulating means comprising an annular member of thermally insulating material interposed between said second portion and said engaging portion of said compressing means so that the latter may effect compressing of said second portion without being in heat-exchanging engagement therewith.
 8. A lighter as defined in claim 1, wherein said burner means includes a surface portion proximal to said outlet and which is heated by the flame resulting upon ignition of fuel issuing from said outlet; said vaporizing means being in heat-exchanging contact with said burner unit for exchanging heat with said surface portion.
 9. A lighter as defined in claim 8, wherein said vaporizing means comprises a vaporizing element composed of a porous material having good thermal conductivity. 